A conventional fuel supply apparatus using a fuel injection valve is shown in FIGS. 22 and 23.
FIG. 22 is an upper plan view in the case of seeing a fuel supply apparatus from the above, and FIG. 23 is a vertical cross sectional view of a main portion in a line Z—Z of FIG. 22.
Reference numeral 80 denotes a first throttle body in which a first intake path 81 is provided therethrough in a vertical direction, in FIG. 23. The first intake path 81 is opened and closed by a first throttle valve 83 attached to a first throttle valve shaft 82.
An upper opening 81a of the first intake path 81 communicates with an inner side of an air cleaner box 84 arranged in an upper side via a duct or the like, a lower opening 81b of the first intake path 81 is connected to a first intake pipe 85 bent toward the other side A in accordance with extending close to a lower side in FIG. 23, and a downstream side of the first intake pipe 85 is connected to a first cylinder 86, for example, constituting a V-type engine.
Reference symbol J1 denotes an electromagnetic type first fuel injection valve attached to the first throttle body 80. A lower side of the first fuel injection valve J1 is inserted and supported to the first throttle body 80, and an upper side thereof is inserted and supported to a first fuel supply pipe 87. The first fuel injection valve J1 is pinched by the first throttle body 80 and the first fuel supply pipe 87 by screw fixing the first fuel supply pipe 87 to the first throttle body 80 via a screw 88.
Further, it is necessary that the fuel injected by the first fuel injection valve J1 is supplied along a curve of the first intake pipe 85 as much as possible. Accordingly, the first fuel injection valve J1 is first arranged in one side B of the first throttle body 80, that is, one side outer surface 80b. Further, secondly, a lower injection hole Ja of the first fuel injection valve J1 is arranged so as to be inclined toward a center of the first intake path 81. In other words, the first fuel injection valve J1 is arranged in such a manner that the first throttle body 80 exists in one side outer surface 80b and is inclined so as to lower the left side thereof in FIG. 23.
In this case, a first fuel distribution path 87a is provided through within the first fuel supply pipe 87, and a fuel inflow path 88 is connected to an opening in a left side C in FIG. 22 of the first fuel distribution path 87a. 
Further, the fuel having the pressure increased by the fuel pump (not shown) is supplied to the fuel inflow path via a fuel pipe 89.
Reference numeral 90 denotes a second throttle body in which a second intake path 91 is provided through in a vertical direction in FIG. 23. The second intake path 91 is opened and closed by a second throttle valve 93 attached to a second throttle valve shaft 92.
An upper opening 91a of the second intake path 91 communicates with an inner side of the air cleaner box 84 arranged in an upper side via a duct or the like, a lower opening 91b of the second intake path 91 is connected to a second intake pipe 95 bent toward one side B in accordance with extending toward a lower side in FIG. 23, and a downstream side of the second intake pipe 95 is connected to a second cylinder 96, for example, constituting a V-type engine.
Reference symbol J2 denotes an electromagnetic type second fuel injection valve attached to the second throttle body 90. A lower side of the second fuel injection valve J2 is inserted and supported to the second throttle body 90, and an upper side thereof is inserted and supported to a second fuel supply pipe 97. The second fuel injection valve J2 is pinched by the second throttle body 90 and the second fuel supply pipe 97 by screw fixing the second fuel supply pipe 97 to the second throttle body 90 via the screw 88.
Further, it is necessary that the fuel injected by the second fuel injection valve J2 is supplied along a curve of the second intake pipe 95 as much as possible. Accordingly, the second fuel injection valve J2 is first arranged in the other side A of the second throttle body 90, that is, the other side outer surface 90a. Further, secondly, a lower injection hole Ja of the second fuel injection valve J2 is arranged so as to be inclined toward a center of the second intake path 91. In other words, the second fuel injection valve J2 is arranged in such a manner that the second throttle body 90 exists in the other side outer surface 90a and is inclined so as to lower the left side thereof in FIG. 23.
In this case, a second fuel distribution path 97a is provided through within the second fuel supply pipe 97.
As mentioned above, in the structure in which the respective cylinders are arranged in both sides of the intake path such as the V-type engine, the fuel injection valves are arranged so as to oppose in one side B and the other side A of the intake path in accordance therewith.
Further, the first throttle valve shaft 82 and the second throttle valve shaft 92 are arranged at the coaxial position in FIG. 22, a left end portion 82c of the first throttle valve shaft 82 is arranged so as to protrude to a left side C further from the left side outer surface 80c of the first throttle body 80, and a driven lever 98 is fixed to the left end portion 82c. 
Further, a right end portion 92d of the second throttle valve shaft 92 is arranged so as to protrude to a right side D further from the right side outer surface 90d of the second throttle body 90, and a throttle drum 99 operated by a driver is fixed to the right end portion 92d. 
Further, the throttle drum and the driven lever 98 arranged so as to oppose to the throttle drum 99 are connected so as to synchronously rotate by a synchronously connecting rod 100.
In this case, reference numeral 101 denotes a valve opening wire in which one end is engaged to the throttle drum 99 and the other end is engaged to an accelerator grip (not shown), and reference numeral 102 denotes a valve closing wire engaged in the same manner.
Accordingly, in the case that the driver pulls the valve opening wire 101, the throttle drum 99 is rotated in a clockwise direction in FIG. 23, and the rotation of the throttle drum 99 synchronously rotates the driven lever 98 via the synchronously connecting rod 100, whereby the first and second throttle valves 82 and 83 synchronously open the first and second intake paths 81 and 91.
Further, in the case that the driver pulls the valve closing wire 102, the throttle drum 99 is rotated in a counterclockwise direction in FIG. 23, and the rotation of the throttle drum 99 synchronously rotates the driven lever 98 via the synchronously connecting rod 100, whereby the first and second throttle valves 82 and 83 synchronously close the first and second intake paths 81 and 91.
Further, the first fuel distribution path 87a of the first fuel supply pipe 87 and the second fuel distribution path 97a of the second fuel supply pipe 97 are connected by a fuel communicating pipe 103.
The fuel communicating pipe 103 is connected to the second fuel distribution path 97a of the second fuel supply pipe 97 from the first fuel distribution path 87a of the first fuel supply pipe 87 while by passing an outer side of the right side D further from the right side outer surface 80d of the first throttle body 80 and an outer side of the other side A further from the other side outer surface 80a of the first throttle body 80.
In accordance with the conventional fuel supply apparatus mentioned above, when the driver operates the valve opening wire 101, the throttle drum 99 and the driven lever 98 are synchronously rotated in the clockwise direction, whereby the first throttle valve 83 opens the first intake path 81, and the second throttle valve 92 opens the second intake path 91. Further, in the case that the driver operates the valve closing wire 102, the throttle drum 99 and the driven lever 98 are synchronously rotated in the counterclockwise direction, whereby the first throttle valve 83 closes the first intake path 81 and the second throttle valve 92 closes the second intake path 91.
Further, the fuel having the pressure increased by the fuel pump (not shown) is supplied to the first fuel distribution path 87a within the first fuel supply pipe 87 via the fuel pipe 89 and the fuel inflow path 88, the fuel is injected toward the first intake pipe 85 from the injection hole Ja of the first fuel injection valve J1. In this case, since the first fuel injection valve J1 including the injection hole Ja is arranged in one side outer surface 80b of the first throttle body 80 in an inclined manner as mentioned above, it is possible to inject and supply the fuel injected from the injection hole Ja along the curve of the first intake pipe 85.
On the other hand, a part of the fuel existing within the first fuel distribution path 87a is supplied to the second fuel distribution path 97a of the second fuel supply pipe 97 via the fuel communicating path 103, and the fuel is injected toward the second intake pipe 95 from the injection hole Ja of the second fuel injection valve J2. In this case, since the second fuel injection valve J2 including the injection hole Ja is arranged in the other side outer surface 90a of the second throttle body 90 in the inclined manner as mentioned above, it is possible to inject and supply the fuel injected from the injection hole Ja along the second intake pipe 95.
In accordance with the conventional fuel supply apparatus mentioned above, the fuel communicating pipe 103 for communicating of the first fuel distribution path 87a of the first fuel supply pipe 87 and the second fuel distribution path 97a of the second fuel supply pipe 97 is arranged so as to bypass the one side B from the one side outer surface 80b, the right side D from the right side outer surface 80d and the other side A from the other side outer surface 80a of the first throttle body 80.
In other words, the first fuel distribution pipe 87a and the second fuel distribution path 97a communicates by the fuel communicating pipe 103 bypassing the outer side of the first throttle body 80 and the outer side of the second throttle body 90. The fuel communicating pipe 103 is arranged in the manner mentioned above because of the conditions that the air cleaner box 84 is arranged above the fuel communicating pipe 103 and thus the upper portion is limitedly used, that the first intake pipe 85 and the second intake pipe 95 are arranged below the fuel communicating pipe and thus the lower portion is limitedly used, and that the throttle drum 99 and the driven lever 98 are arranged in an adjacent space between the left side outer surface 80c of the first throttle body 80 and the right side outer surface 90d of the second throttle body 90, the valve opening wire 101 and the valve closing wire 102 are also arranged therein and thus the adjacent space is limitedly used.
In the case that the fuel communicating pipe 103 is arranged so as to bypass the outer sides of the throttle bodies 80 and 90 as mentioned above, the following problems are generated.
(1) There is a risk that a pipe length of the fuel communicating pipe 103 is elongated, the fuel communicating pipe 103 tends to be affected by a temperature of an ambient atmosphere of the engine, vapor is generated in the fuel flowing within the fuel communicating pipe, and the fuel injection particularly from the second fuel injection valve J2 lacks stability.
(2) Particularly in the case of being used as the fuel supply apparatus in which the receiving space of the apparatus is largely limited in comparison with a four-wheel vehicle, such as that for a two-wheel vehicle, there is a risk that the fuel communicating pipe 103 interferes with the other constituting members such as a frame, a tank or the like, so that a freedom of arranging the fuel pipe is deteriorated.
(3) Particularly in the case of being used in the structure in which the fuel supply apparatus is directly exposed to the exterior, such as that for the two-wheel vehicle, a protecting member is necessarily provided so as to prevent the fuel communicating pipe 103 and the passenger from being in contact with each other or prevent the fuel communicating pipe from being brought into contact with the other member, and there is a risk that the fuel communicating pipe exposes from the side portion of the two-wheel vehicle so as to deteriorate an outer appearance.